Fact Sheet ST-362
November 1993
Liquidambar styraciflua ‘Rotundiloba’
‘Rotundiloba’ Sweetgum1
Edward F. Gilman and Dennis G. Watson2
INTRODUCTION
‘Rotundiloba’ or Roundleaf Sweetgum grows to a
height of about 75 feet and may spread to 50 feet (Fig.
1). The beautifully glossy, star-shaped leaves have
rounded tips and turn deep purple in the fall (USDA
hardiness zones 6 and 7) and early winter (USDA
hardiness zones 8 and 9). Branches are covered with
characteristic corky projections.
GENERAL INFORMATION
Scientific name: Liquidambar styraciflua
‘Rotundiloba’
Pronunciation: lick-wid-AM-bar
sty-rass-ih-FLOO-uh
Common name(s): ‘Rotundiloba’ Sweetgum
Family: Hamamelidaceae
USDA hardiness zones: 5B through 10A (Fig. 2)
Origin: native to North America
Uses: large parking lot islands (> 200 square feet in
size); wide tree lawns (>6 feet wide); medium-sized
parking lot islands (100-200 square feet in size);
recommended for buffer strips around parking lots or
for median strip plantings in the highway; shade tree;
specimen; sidewalk cutout (tree pit); residential street
tree; no proven urban tolerance
Availability: somewhat available, may have to go out
of the region to find the tree
Figure 1. Middle-aged ‘Rotundiloba’ Sweetgum.
DESCRIPTION
Height: 50 to 70 feet
Spread: 35 to 45 feet
1.
This document is adapted from Fact Sheet ST-362, a series of the Environmental Horticulture Department, Florida Cooperative Extension Service,
Institute of Food and Agricultural Sciences, University of Florida. Publication date: November 1993.
2.
Edward F. Gilman, associate professor, Environmental Horticulture Department; Dennis G. Watson, associate professor, Agricultural Engineering
Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville FL 32611.
Liquidambar styraciflua ‘Rotundiloba’ -- ‘Rotundiloba’ Sweetgum
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Figure 2. Shaded area represents potential planting range.
Crown uniformity: symmetrical canopy with a
regular (or smooth) outline, and individuals have more
or less identical crown forms
Crown shape: oval; pyramidal
Crown density: moderate
Growth rate: medium
Texture: coarse
Foliage
Leaf arrangement: alternate (Fig. 3)
Leaf type: simple
Leaf margin: lobed; entire
Leaf shape: star-shaped
Leaf venation: palmate
Leaf type and persistence: deciduous
Leaf blade length: 4 to 8 inches
Leaf color: green
Fall color: orange; purple; red; yellow
Fall characteristic: showy
Flower
Flower color: green; yellow
Flower characteristics: inconspicuous and not
showy; spring flowering
Fruit
There is no fruit on this tree.
Trunk and Branches
Trunk/bark/branches: droop as the tree grows, and
will require pruning for vehicular or pedestrian
clearance beneath the canopy; not particularly showy;
should be grown with a single leader; no thorns
Pruning requirement: needs little pruning to develop
a strong structure
Breakage: resistant
Current year twig color: brown; reddish
Current year twig thickness: medium
Wood specific gravity: 0.52
Liquidambar styraciflua ‘Rotundiloba’ -- ‘Rotundiloba’ Sweetgum
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is apparently fruitless. Be careful when locating
Sweetgum as a street tree since its large, aggressive
roots may lift curbs and sidewalks. Plant trees 8 to 10
feet or more from curbs, sidewalks and driveways.
Sweetgum is rarely attacked by pests, and tolerates
wet soils. It is difficult to transplant in the fall and
from well-drained field soil since roots can be coarse
and deep. Consider planting from containers or
transplanted when young. It is native to bottomlands
and moist soils and tolerates only moderate drought.
It is recommended only for acid soils since chlorosis
develops on soils with a pH over 7.5. It grows very
well in clay soils which hold moisture. Liquidambar
spp. grows very well for several years after
transplanting in parts of Texas and in other areas with
a high pH subsoil but chlorosis often develops as some
roots establish themselves in the alkaline soil.
Figure 3. Foliage of ‘Rotundiloba’ Sweetgum.
Culture
Light requirement: tree grows in part shade/part sun;
tree grows in full sun
Soil tolerances: clay; loam; sand; slightly alkaline;
acidic; extended flooding; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: moderate
Other
Roots: surface roots can lift sidewalks or interfere
with mowing
Winter interest: tree has winter interest due to
unusual form, nice persistent fruits, showy winter
trunk, or winter flowers
Outstanding tree: tree has outstanding ornamental
features and could be planted more
Invasive potential: little, if any, potential at this time
Verticillium wilt susceptibility: not known to be
susceptible
Pest resistance: long-term health usually not
affected by pests
USE AND MANAGEMENT
Sweetgum makes a nice park, campus or
residential shade tree for large properties. Could be a
superior tree to the species, especially for street tree
use or near other paved surfaces, since ‘Rotundiloba’
Other cultivars have been selected for their fall
color or growth habit, but they all set fruit: ‘Burgundy’
- burgundy red fall color, holds leaves late into fall;
‘Festival’ - narrow upright growth habit, peach-colored
fall foliage; ‘Palo Alto’ - pyramidal, symmetrical
growth, bright orange fall color.
Pests
Bagworm makes sacks by webbing together pieces
of leaves. The insects live in the sacks while they
feed. Small numbers of insects may be picked off by
hand.
Fall webworm webs over portions of large
branches or may completely cover small branches.
The insects feed on leaves inside the nest. If practical,
nests can be pruned out while small and when the
insects are inside. A few nests in large trees are not
serious.
Leaf miner causes brown blotches on leaves. If
injury is caused by leaf miner the browned upper and
lower leaf surfaces will be completely separate when
the leaf is torn in two.
Cottony-cushion scale, Sweetgum scale, and
walnut scale can infest the branches.
Tent caterpillars make nests to live in but leave
the nests to feed. Prune out nests at the tips of small
branches. Do not burn the nest while it is still in the
tree since this will damage the tree and could start an
uncontrolled fire.
Liquidambar styraciflua ‘Rotundiloba’ -- ‘Rotundiloba’ Sweetgum
Diseases
Sweetgum may be attacked by canker diseases.
These diseases cause sunken areas on the trunk and
some cause profuse "bleeding". Infected bark and
sapwood will be brown and dead. There is no
chemical control for canker diseases. Severely
infected trees will die. Prune cankers out of lightly
infected trees. Maintain tree health by watering and
fertilizing.
Leaf spots of various types may attack Sweetgum
but are not serious. Rake up infected leaves.
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